NOTOPLITES 355 



in its less numerous spines and in the raised border to the aperture ; in the shape of the 

 scuta and in the absence of axillary avicularia. 



All three species agree in the possession of areas (Fig. 16 B) in the lateral walls 

 corresponding to the muscle attachments (see p. 339). 



B 







L 



•3 mm 







± 



± 



B 



j 



•3mm 



Fig. 16. A, B. Notoplites crasstscutus sp.n. St. 160, Shag Rocks. A. Basal view of axillary avicularium. 

 Underlying zooecia outlined, and lettered according to Harmer's scheme. B. Oblique basal view of 

 parts of two zooecia. 



f.av. frontal avicularium of zooecium F, o.mu. occlusor muscle, p.ntu. parietal muscles, r.c. rootlet- 

 chamber in thickness of wall, sc. scutum. 



11. Notoplites perditus (Kluge). 



Scrupocellaria perdita Kluge, 1914, p. 613, text-fig. 2. 

 Notoplites? perditus Harmer, 1923, p. 353. 



Station distribution. Not represented in the Discovery collections. 



Geographical distribution. Southern Ocean, 2450 m. (Kluge). 



Notoplites perditus, which I have not seen, has quite conspicuous marginal avicularia 

 and a small uncalcified area in the ectooecium, thus resembling the members of the 

 N. antarcticus group (see Key p. 340, bifurcation 2). Kluge does not mention internal 

 spines, but as he mentions them in only one of the four members of the group, and as 

 he described N. perditus from a small fragment which was lost after only a preliminary 

 examination, they may yet prove to be present. Frontal avicularia appear to have been 

 absent, and the rounded scutum with a small, sharply demarcated, distal lobe would, 

 if constant, be characteristic. 



